Hopefully this is an easy one. I have a series of charts in MS Excel that point to data on the same worksheet. The data on the worksheet is calculated using a VBA function. W
It's possible that the issue is the argument list of getWeekValue, which includes only the week number and the data stream.
If you add a third argument, worksheetDate, then Excel's recalculation engine will be hit on the side of the head with the fact that getWeekValue uses the value held in worksheetDate. In your current implementation, this fact is held only in the VBA code, where it is probably invisible to the recalculation engine.
I write this so hedgingly because I am not privy to the inner workings of the recalculation engine. (Maybe someone who knows about this better than I can comment on my speculation) But I did do a test, in which getWeekValue does have that third argument, and the chart does recalculate properly. Nice added benefit of this approach: you can remove all that other VBA event management. -HTH